Friday, 8 October 2010

Coloured malts (part four)

Back to coloured malts again. I told you I could drag this topic out for weeks. Today it's the turn of brown, amber and crystal malts. Some of my favourites, yet also some of the trickiest to pin down. You'll find out why in a minute.

"Of brown and amber malt I need say but little. These are used for flavour rather than colour, and the products of different manufacturers vary considerably in both respects. Such malts enter, however, into the composition of some of the best blends of black beer grists. The irregularity in their character, which was at one time very marked, is now partially remedied, and there are now on the market excellent samples of both types of material, and the increased reliability lately observable will, no doubt, do much to restore confidence in, and extend the use of, these materials. I have met with some samples of brown malt which fade considerably on storage, but others, and the better made, appear to possess substantially the same permanency of colour as black malt. In any case, the colour question is a minor one, as any colour which they may give is generally swamped by the much greater tintorial value of the black malt with which they are used."
"Journal of the Institute of Brewers vol. 13, 1907", pages 493-494.

See why they're so hard to pin down? Because they varied so much. For someone like me, who's interested in attempting to recreate historical beers, this presents somewhat of a problem. As no general rules apply, you'd need to determine the qualities of each individual manufacturers malt.

This is something that's been slowly percolating through my thick skull. That the next logical step in my quest is to look at malting records. I wonder how many still exist? And are they the right ones? Page, French and Baird are maltsters who supplied brown malt to London brewers. They would be the ones to start with.

"Crystallised malt differs from the preceding varieties, inasmuch as it is frequently used, not only in black but in mild beers, in which it is useful as giving a rich nutty flavour. I consider it extremely valuable as a constituent of mild beer grist, where the colour of that beer will permit its use. In some cases from 2—5 per cent, of crystal malt is employed with great advantage, and I think the expense is warranted. It is, I believe, the practice of some manufacturers to use a sugar solution in the preparation of this malt, but perfectly good material may be made without it, and I see no advantage in its employment; indeed, I think I have seen just as good malt made without sugar as with it. The weight of crystal malt is, as a rule, 250—280 lb. a quarter. There is a considerable difference between the extract yielded when mashed alone and when mashed with pale malt. When extracted alone, the yield averages about 50 lb.; when mashed with malt, it may be as high as 80 lb., these extracts being calculated as the weight of 336 lb. This is a matter of no importance in practice, as crystal malt is always used in the mash-tun with pale malt. The actual extract given by crystal malt on natural weight in mash-tun practice is probably about 50 lb. The colour of a 10-per-cent. solution examined in a 1-inch cell varies from 100°—250°. I think a minimum colour of 125° would be a fair basis for purchase."
"Journal of the Institute of Brewers vol. 13, 1907", page 494.
100° to 250° is quite a big colour range. To put those numbers into context (as the colour of malt is no longer measure this way) black malt was between 1000 and 1500°. Yet another problem for recreationists. Which type of crystal malt was a brewery using? The only possible clue, other than chasing down the malting records, is the weight per quarter. Assuming, that is, that the malts with a lighter weight would be of a darker shade. But that is, at best, a very crude method.

"In all these coloured malts there is much difference in tenderness to be observed as well as in evenness of roasting. It is only necessary to place a sample in a barley cutter to see the irregularity of any sample. In the cheap malts of this class very serious defects of this character may sometimes be noted, but if made from good grain, evenly malted, very considerable regularity is obtainable. It is to be noted that it has been found quite impossible to produce satisfactory crystal material, except from malted grain. All efforts to produce this from barley have hitherto been futile."
"Journal of the Institute of Brewers vol. 13, 1907", pages 494-495.
Cheeky bastards, trying to make crystal from unmalted grains.

"In speaking of the permanency of colour produced by malt, I do not overlook the fact that there is in certain cases a very definite loss of colour occurring in black and, indeed, other beers on storage. This is, I believe, often due to bacterial infection, for it has been long ago observed by many that infected beers are very liable to become pale on storage. Some of this decrease of colour may be due to increase of the acid reaction of the beer, but that bacteria do, apart from their influence upon acidity, actually decolorise beer is, I think, quite clearly established. The same remark applies to some types of wild yeast infection, and, though with less force, to particular types of actual brewing yeast. There are yeasts in certain breweries which have a very marked decolorising influence upon worts into which they are introduced. Such yeasts are generally of very attenuative type. Indeed, they often have characteristics which seem to indicate a tendency to revert to the original type of wild yeast from which, no doubt, all culture yeasts have been in the first instance derived. These types are, however, very unusual, and the ordinary pitching yeast of a well-regulated brewery removes but little colour from the beer, either during primary or secondary fermentation."
"Journal of the Institute of Brewers vol. 13, 1907", page 495.

This is all new to me. I'd never imagined that bacteria could remove colour from a beer. Let alone pitching yeast. I'd naively assumed that colour was pretty well permanent. But more of that in the next installment. When we consider the colouring qualities of roasted malt and roasted barley. Lawrence Briant  (the author of the article I've been quoting like crazy) carried out a series of fascinating experiments to see what differences he could spot between these two colouring malts.


Gary Gillman said...

All very interesting. His comments about de-colorization don't make sense to me, and I have never heard anything like this. One would think it would have been remarked by the hundreds of writers we have now seen, many experienced practical brewers, writing in different centuries - yet nary a word. His theory that certain yeast types are capable of doing this is speculation IMO and I doubt it can be substantiated.

However, I'll offer a theory of my own, which has been substantiated in my own experience. Authors on the production of distilled spirits have noted that caramel, used to impart or standardize colour in rum and whisky notably, can fade out of the drink over time. This especially can occur where the bottles are exposed to strong light for a considerable time - there is a photosynthesis reaction which destroys the colour somehow.

Across the street from where I write, in the outlet there of the Liquor Control Board of Ontario, there was a window display a couple of years back of well-known brands of Canadian and American whisky. One, a 12 year old whisky which has a dark colour, had almost completely faded, to a pale watery tan - the difference from the "fresh" product was striking. There was a bottle of bourbon next to it, and it was as dark as when first packaged. Bourbon by law cannot have any caramel in it, the colour is all-natural, from the barrel.

I think the beers Briant observed which lost colour had been treated with spirit caramel (to darken them) and the caramel finally faded from the drink, whether under influence of light, or other factors. If light was not the cause in all cases, e.g., for barreled beers, yeast may have been in the sense that in that pre-pasteurizing era, slow secondary and further ferments may have consumed the sugar in the caramel. For this to happen though, no very exotic yeasts were required.

This is what I think at any rate, I could be wrong, but I don't think so.


Ron Pattinson said...

Gary, I'll be posting the details of his experiments with colour permanency soon. They were performed on beers coloured with roasted malt and roasted barley.

Gary Gillman said...

I look forward to that Ron. Implicit in my remarks is that caramel probably was often used without always being disclosed (perhaps even to him).

I certainly accept that some coloured malt was inherently unstable or of poor quality as he stated, e.g., it makes sense that for some blown malts, carbonized particulate matter in solution could drop out over time.

But as for de-colouring due to the action of special yeasts, I doubt that very much. I've never experienced that in 40 years of drinking beer including many bottle-conditioned and weird types.

Look forward to more.


Graham Wheeler said...

The statement: "as the colour of malt is no longer measure this way"

Is almost certainly incorrect. Maltsters still measure colour visually because the usual electronic method does not work with the standard IoB/EBC/ASBC trial mash. Basically the stuff is mashed and measured. As there is no boil there is lots of protein in solution / suspension. Not only does this protein scatter the 430nm light that is shone through the sample for electronic measurements but protein has an absorption line at, yep, 430nm.

Anyway, electronic methods give errors with the standard test mash. So maltsters have stuck with the visual method.

That is the reason for Americans using Lovibond (visual) for malt and SRM (electronic) for beer. Despite what many American home brewers think, Lovibond and SRM are two separate and widely divergent scales at anything above lager colour.

Americans have an advantage here, because they still use the S52 scale. Although the S52 scale has possibly had several realignments since 1907, all they have to do is divide your numbers by two to give colour in terms of their beloved Lovibond scale normalised to half-inch path length.

Yes, yeast does remove colour from beer - all to do with ionic charges and all that - but it is not enough to worry about and is compensated for by the small amount of additional colour generated to the boil.

Colloidal stability (of colour in beer) is a science all to itself, which is more important with something like medicines where you do not want the ingredients to separate and stratify, raising the possibility of poisoning someone with a concentrated dose.

Old-fashioned burnt sugar caramel (Type a in Europe; type 1 in America) is not very stable in beer. Only some variants of type c (type 3) caramel are stable in beer. All to do with ionic charges yet again.

As for roasted malt, I have no idea; I guess that it must be stable, but I am all ears or eyes.

Of course, stability is not the same as sunlight bleaching, which will bleach just about anything.

Gary Gillman said...

I'm fascinated to see this discussion about colour and its measurement in beer, the technics are far more involved than I would have thought and I am at sea in this area. Personally, I've never given a fig about colour. Within reasonable bounds, okay, e.g., a stout should be blackish-brown I suppose but I don't care what colour beer is really, I care what it tastes like. I don't care about consistency in this regard either. Can commercial brewers be giving too much importance to this question? Methinks they are putting the emphasis on the syllAble.


Gary Gillman said...

I meant (Ron, do you never edit? :)), on the wrong syll-A-ble). The very worthy Tuborg Pure Gold must have diverted my attention, it is brewed in Turkey under supervision of Carlsberg in Copenhagen, but excellent of its type. Must be that high quality Smyrna barley, and I must thank Martyn for mentioning that Turkey is a historical barley cultivation area.


Thomas Barnes said...

Reading between the lines, it's interesting to notice what they didn't know about brewing chemistry in 1907.

Of course you can't make crystal malt from raw barley! Enzyme creation during malting is a necessary precursor to saccharification of the starches during the crystal malting process.

@Gary: I've never seen bacterial contamination causing color change either. Your idea about light causing the change might be spot on.

Possibly though, the presence of certain bugs might encourage flocculation (since the bacteria serve as nucleation points) which would help precipitate suspended colorant particles.

Alternately, the presence of bugs in the beer might increase haze which would give the optical illusion of lighter color.